This study compared three near-infrared (NIR) spectrometers - Jaz, QE65000, and NIRQuest - for measuring sucrose concentration. All spectrometers showed a linear decrease in absorption with increasing sucrose concentration. Multiple linear regression improved correlations. Wavelengths of 959nm, 959nm, and 1363nm produced the highest coefficients of determination for Jaz, QE65000, and NIRQuest, respectively. Combinations of wavelengths generated the best calibration algorithms, with NIRQuest showing the highest coefficient of determination overall. The study concludes the spectrometers can effectively measure sucrose concentration using NIR spectroscopy.

1. COMPARATIVE STUDY BETWEEN NEARINFRARED(NIR) SPECTROMETERS IN THE
MEASUREMENT OF SUCROSE CONCENTRATION

2. INTRODUCTION

3. NIR Spectroscopy I
A spectroscopic method that uses the near-infrared region
of the electromagnetic spectrum (from about 800 nm to
2500 nm).
NIR spectra have only a few significant peaks, but they
are exceptionally information-rich due to the number of
overlapping absorption bands.

4. NIR Spectroscopy II
NIR can typically penetrate much further into a sample
than mid infrared radiation due to the low coefficient of
absorbance.
NIR radiation has less energy/photon but does excite
molecular vibrations.
NIR measurements are non-destructive and samples are
not altered and can be reused.

5. The Importance of Measuring
Sugar Concentration in Fruit I
Commonly used in the wide range of crops.
The important aspect to test the maturity of fruit and
obtain the right time to harvest it.
The percentage of sugar (oBrix), indicates the sweetness of
the fruit.

6. The Importance of Measuring
Sugar Concentration in Fruit II
Contribute to the calculation of sugar-acid ratio which is
one of the step needed to test the maturity of fruit.
One critical element of the ripening involves the conversion
of starches to sugars.
The example of starch test is shown in Figure 1.

7. Objectives
1. To compare response analysis between lower and same
range of NIR wavelength (Jaz and QE65000)
spectrometer.
2. To identify response analysis of higher range of
wavelength (NIRQuest) spectrometer.
3. To compare response analysis between lower and higher
range of NIR wavelength spectrometer.

8. Problem
Statement
The NIR spectrometers are widely used in the spectroscopy
field.
The calibration transfer between NIR spectrometers
should be practiced in spectroscopy field to improve the
efficiency in energy, time and work.
The comparative study between NIR spectrometers will
give huge contribution to the calibration transfer.

9. MATERIALS
AND
METHOD

10. Apparatus and
Material Background I
The apparatus used in the experiment are:
QE65000 Spectrometer (650 – 1100 nm), Figure 2.
NIRQuest512-2.2 Spectrometer (900 – 2200 nm), Figure 3.
Handheld Refractometer, Figure 4.
The apparatus used in the reference taken:
JAZ-COMBO Spectrometer (650 – 1100 nm), Figure 5.
*** The characteristics and properties of NIR spectrometers are
shown in the Table 1.

11. Apparatus and
Material Background II
The material used in the experiment is:
Sucrose:
The molecule is a disaccharide sugar composed of the
monosaccharides glucose and fructose with the molecular
formula C12H22O11.
*** The skeletal formula for sucrose is shown in the Figure 6.

12. Experiment
Setup
The overall experimental setup was conducted using
spectroscopic instrumentations from Ocean Optics.
The setup is illustrated in Figure 7.
The response was due to mixture between water with
sucrose for different type of spectrometer.
The characteristics of sucrose sample used in the
experiment are tabulated in Table 2.

13. Methodology
The flow chart of the experiment is shown in the Figure 8.
The experiment was conducted only for the calibration
data.

14. RESULTS AND
DISCUSSIONS

15. Response Analysis between
Jaz and QE65000 Spectrometer I
Significant results were managed to be located at
wavelength between approximately 940 and 985 nm.
Figure 9(a) and Figure 9(b) shows the resultant linear
regression generated between absorbance and sucrose
concentration by using Jaz and QE65000 spectrometer
respectively.

16. Response Analysis between
Jaz and QE65000 Spectrometer II
λ = 959 nm managed to generate the highest coefficient
of determination for sucrose by using:
Jaz spectrometer : R2 = 0.9794; RMSE = 1.43
QE65000 spectrometer : R2 = 0.956 ; RMSE = 2.15
The pattern behaviour of linear relationship between
absorbance and the sucrose concentration against
wavelengths for Jaz and QE65000 spectrometer are shown
in Figure 10(a) and Figure 10(b) respectively.

17. Response Analysis between
Jaz and QE65000 Spectrometer III
It can be seen that the correlation between absorbance
and sucrose concentration starts to loose its linearity once it
has moved further than 960 nm.
Further analysis through the application of Multiple Linear
Regression (MLR) has successfully improved the correlation
for sucrose measurement.

18. Response Analysis between
Jaz and QE65000 Spectrometer IV
The highest efficiency algorithm has been identified by
using different wavelengths:
Jaz spectrometer: 730, 830, 915, and 960 nm
QE65000 spectrometer: 909 and 960 nm

19. Response Analysis between
Jaz and QE65000 Spectrometer V
The calibration algorithm, R2, and RMSE for calibration
(RMSEC) for both spectrometers are as follows:
Jaz spectrometer:
Sucrose concentration (°Brix) = 122 + 1375ƛ730 - 942ƛ830 +
855ƛ915 - 736ƛ960
(R2= 0.992; RMSEC = 0.907 °Brix);

20. Response Analysis between
Jaz and QE65000 Spectrometer VI
QE65000 spectrometer:
Sucrose concentration (°Brix) = 135 + 777ƛ909 - 824ƛ960
(R2= 0.995; RMSEC = 0.760 °Brix)
The linearity of the calculated model are illustrated in
Figure 11(a) and Figure 11(b) for Jaz spectrometer and
QE65000 spectrometer respectively.

21. Response Analysis of
NIRQuest Spectrometer I
Significant result is managed to be located at wavelength
between approximately 980 and 1700 nm.
Figure 12 shows the resultant linear regression generated
between absorbance and sucrose concentration by using
NIRQuest spectrometer.

22. Response Analysis of
NIRQuest Spectrometer II
λ = 1363 nm managed to generate the highest coefficient
of determination and lowest RMSE for sucrose by using:
NIRQuest spectrometer : R2 = 0.813; RMSE = 4.64
The pattern behaviour of linear relationship between
absorbance and the sucrose concentration against
wavelengths for NIRQuest spectrometer is shown in Figure 13.

23. Response Analysis of
NIRQuest Spectrometer III
The correlation between absorbance and sucrose
concentration starts to loose its linearity once it has moved
further than 1400 nm.
Further analysis through the application of Multiple Linear
Regression (MLR) has successfully improved the correlation
for sucrose measurement.

24. Response Analysis of
NIRQuest Spectrometer IV
The highest efficiency algorithm has been identified by
using different wavelengths:
NIRQuest spectrometer : 980, 1156, 1163, 1195, 1337, 1350,
1395, 1606, 1670, 1676, and 1682 nm.

25. Response Analysis of
NIRQuest Spectrometer V
The following are the calibration algorithm, R2, and RMSEfor
calibration (RMSEC):
NIRQuest spectrometer
Sucrose concentration (°Brix) = 171 + 79ƛ980 + 2909ƛ1156 - 1550ƛ1163
- 422ƛ1195 + 445ƛ1337 - 1783ƛ1350 + 310ƛ1395 – 41.8ƛ1606 + 298ƛ1670 298ƛ1676 + 195ƛ1682
(R2 = 0.982; RMSEC = 1.613 °Brix)
The linearity of the calculated model is illustrated by Figure 14.

26. Response Analysis between
NIR Spectrometers I
By comparing the three spectrometers, all of them show
the same properties :
The absorption of a specific range of NIR wavelength
decreases linearly with the increases of sucrose concentration.
Further analysis through MLR has successfully improved
the correlation for sucrose measurement.

27. Response Analysis between
NIR Spectrometers II
The ascending order of highest coefficient determination
produced are by using NIRQuest, Jaz, and QE65000
spectrometers.

28. CONCLUSIONS
AND
RECOMMENDATIONS

29. Conclusions I
Wavelength that generate the highest coefficient of
determination :
Jaz spectrometer: 959 nm (R2 = 0.9794; RMSE = 1.43)
QE65000 spectrometer : 959 nm (R2 = 0.956 ; RMSE = 2.15)
NIRQuest spectrometer : 1363 nm (R2 = 0.813; RMSE = 4.64)

30. Conclusions II
Combination of NIR wavelength that produce the highest
coefficient of determination:
Jaz spectrometer : ƛ=730, 830, 915, and 960 nm
(R2= 0.992; RMSEC = 0.907)
QE65000 spectrometer : ƛ=909 and 960 nm
(R2= 0.995; RMSEC = 0.760)

31. Conclusions III
NIRQuest spectrometer : ƛ=980, 1156, 1163, 1195, 1337, 1350,
1395, 1606, 1670, 1676, and 1682 nm
(R2 = 0.982; RMSEC = 1.613)
These wavelengths exert an important combination in
development of calibration algorithm for individual
spectrometer measurement.

32. Recommendations
For future experiment :
record the validation data as well in order to confirm the
prediction.
conduct the experiment by using the sugar content in fruit
to obtain the real experience on how to improve the intrinsic
quality of fruit.

34. Figure 1 : The Example of Starch Test

35. Figure 2 : QE65000 Spectrometer

36. Figure 3 : NIRQuest512-2.2 Spectrometer

37. Figure 4 : Handheld Refractometer

38. Figure 5 : Jaz Spectrometer

39. Table 1 :The characteristics and properties of NIR
spectrometers.
Jaz
QE65000
NIRQuest
Characteristics
-Modular, stackable and
autonomous components
-Czemy-Turner optical bench
-On-board microprocessor
and OLED display
-Replaceable slits and
gratings
-Ethemet and memory
module
-Battery and external memory
module
-200-1100 nm spectral rangegrating dependent
-Resolution 0.14-7.7 nm
(FWHM)
-Peak quantum efficiency
90%
-Back thinned 2DCCD
detector
-Thermoelectric cooling
-6 slit options
-14 grating option
-900-2050 nm spectral range
-Less than 1 nm optical
resolution FWHM
-15000:1 signal to noise
-On board thermoelectric
cooling
-16 bit USB A/D converter
-Crossed czemy-Turner
optical bench
-Various trigger modest
grating options
Application
-Fluorescence
-Biotechnology
-Raman spectroscopy
-DNA sequencing
-Remote sensing
-Dosimetry
-Spectroscopy
-Medical
-Biomedical imaging analysis
-Fluorescence
-Luminescence detection
-Luminescence detection
-Spectroscopy of emission
and absorption lines
spectroscopy

40. Figure 6 : Skeletal Formula for Sucrose

41. Figure 7 : Experiment Setup for NIR
Measurement (Top view)

42. Table 2 :The Sample Characteristics.
Spectrometer
Range of Sucrose
Mean
(°Brix)
n
(Calibration)
Jaz
0.9-35.0
17.1
50
QE65000
0.1-39.1
8.8
50
0.2-38.8
18.8
50
NIRQuest512-2.2

43. Apparatus
setup
Data
analysis
Sample
preparation
Repeat
experiment
with other
spectrometer
Collect
reference
spectrum
Save data
obtained
Reduce
concentratio
n of sucrose
until 50 data
Figure 8 : Flow Chart of Experiment

44. 0.12
y = -0.001394x + 0.1193; R-Sq = 0.9794
Absorbance
0.11
0.10
0.09
0.08
0.07
0
10
20
30
40
Sucrose Conce ntration (Brix)
Figure 9(a) : Linear relationship between absorbance and
concentration of aqueous sucrose at λ = 959 nm by using Jaz
spectrometer

45. 0.165
y = - 0.000714x + 0.1645
0.160
Absorbance
0.155
0.150
0.145
0.140
0.135
0.130
0
10
20
30
40
Sugars conce ntration (Brix)
Figure 9(b) : Linear relationship between absorbance and
concentration of aqueous sucrose at λ = 959 nm by using
QE65000 spectrometer

46. 1.1
Coefficient of Determination
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
920
930
940
950
960
970
980
990
1000
1010
Wave le ngth (nm)
Figure 10(a) : Coefficient of determination generated at
different wavelength for aqueous sucrose concentration by
using Jaz spectrometer

47. Coefficient of Determination
1.0
0.8
0.6
0.4
0.2
0.0
920
930
940
950
960
970
980
990
1000
1010
Wave le ngth (nm)
Figure 10(b) : Coefficient of determination generated at
different wavelength for aqueous sucrose concentration by
using QE65000 spectrometer

48. Calculated Concentration (Brix)
35
30
25
20
15
10
5
0
0
5
10
15
20
25
30
35
Actual Conce ntration (Brix)
Figure 11(a) : Calculated VS actual concentrations of sucrose
by using Jaz spectrometer.

49. Calculated Concentration (Brix)
40
35
30
25
20
15
10
5
0
0
5
10
15
20
25
30
35
40
Actual Conce ntration (Brix)
Figure 11(b) : Calculated VS actual concentrations of sucrose
by using QE65000 spectrometer.

50. 1.30
Absorbance
1.25
y = - 0.006183x + 1.300
1.20
1.15
1.10
1.05
0
10
20
30
40
Sucrose Conce ntration (Brix)
Figure 12 : Linear relationship between absorbance and
concentration of aqueous sucrose at λ = 1363 nm by using NIRQuest
spectrometer.

51. 0.9
Coefficient of Determination
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
1000
1100
1200
1300
1400
1500
1600
Wave le ngth (nm)
Figure 13 : Coefficient of determination generated at
different wavelengths for aqueous sucrose concentration by
using NIRQuest spectrometer.

52. Calculated Concentration (Brix)
40
30
20
10
0
0
10
20
30
40
Actual Conce ntration (Brix)
Figure 14 : Calculated VS actual concentrations of sucrose by
using NIRQuestspectrometer.